As an existing electric steering device, there is a device wherein two coil windings are provided in a motor, a control unit having two inverter circuits that can independently drive the two coil windings is included, the two inverter circuits are controlled in concert, and motor drive is continued using only a normally operating inverter circuit when there is an abnormality. Furthermore, in addition to control unit inverter circuits, an electric power steering device that handles a failure as a dual system is also known (Patent Document 1).